1. Field of the Invention
The present invention relates generally to a wireless communication system. More particularly, the present invention relates to an apparatus and method for dynamic frequency assignment to a low-power Base Station (BS) in a wireless communication system.
2. Description of the Related Art
Currently, a broadband wireless communication system is being considered to deploy more low-power BSs to complement a macro BS. The low-power BS refers to a home or Small Office Home Office (SOHO) base station that is installed in an area having a poor Quality of Service (QoS) because the area is out of the service coverage area of the macro BS or only receives a weak signal. The low-power BS includes a home or office BS and an enterprise BS. The low-power BS provides a portable Internet service to Mobile Stations (MSs) like the macro BS. However, the low-power BS has a feature of a low output, a low capacity, a low price, etc. optimized for a small-scale such as home or SOHO.
Because of the feature of the low output, the low capacity, the low price, etc. of the low-power BS, the number of low-power BSs being installed is increasing. With the increasing number of low-power BSs, there is a need for a continuous network optimization process suitable for frequent installation and removal of the low-power BSs. This need is immediately followed by the need for a function of automatic installation of the low-power BSs for reducing a cost of network setup and a demand for a system that can detect and adapt a change of installation of neighboring low-power BSs. In pursuit of a service provider's demand, the standardization of self organization is now in progress in a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE).
For the low-power BSs having an automatic BS installation and automatic network optimization function to operate adaptively to an adjacent wireless environment during initial installation or operation, a function of dynamic frequency assignment is required. Because the same outdoor system continues to operate, the low-power BSs must take the outdoor system into consideration. Thus, there is a need for a frequency assignment method for minimizing an influence on outdoor BSs while being adaptive to an indoor BS environment and maximizing a system capacity.